A Constitutional Translocation t(1;17)(p36.2;q11.2) in a Neuroblastoma Patient Disrupts NBPF1 , a novel putative tumor suppressor gene Vanessa Andries , Karl Vandepoele , Katrien Staes, and Frans van Roy Molecular Cell Biology Unit, Dept. for Molecular Biomedical Research, VIB/Ghent University, Technologiepark 927, B-9052 Ghent (Zwijnaarde) E-mail: [email protected], [email protected] Neuroblastoma (NB) is the most common extracranial solid tumor in children and is characterized by a number of recurrent genetic alterations: gain of chromosome 17q, amplification of MYCN , and deletion of 1p36. We found that a constitutional translocation t(1;17)(p36.2;q11.2) in a neuroblastoma patient (Laureys et al., 1995) resulted in the disruption of a novel gene, NBPF1 (Neuroblastoma Breakpoint Family, member 1). This gene is built of repetitive elements and is subject of structural variation in the human population. Thorough analysis of genomic sequences revealed that NBPF1 is a member of a recently expanded gene family, with gene copies located on segmental duplications of chromosome 1 (Vandepoele et al., 2005). Both in silico and in vitro analysis failed to identify any rodent orthologs for the human NBPF genes. The members of the NBPF gene family are widely expressed, both in normal and cancerous tissues, including neuroblastoma cells. Our identification of NBPF-interacting proteins may link these genes to important signalling pathways such as the Wnt and NF-kappaB signalling pathways. The high sequence identity between different NBPF paralogs has thus far disabled the analysis of gene-specific expression patterns, but the development of an NBPF1 -specific qRT-PCR assay is in progress. Transfection experiments revealed a cytoplasmic localization of the different NBPF proteins. Constitutive overexpression of different NBPF paralogs resulted in cell death in a variety of cell lines, including MCF7/AZ, HEK293T, and the neuroblastoma cell line IMR-32. We use now a conditional expression system to circumvent the detrimental properties of the overexpressed NBPF proteins and to investigate the process leading to NBPF1-induced cell death. Also, the development of transgenic mice with stable integration of the human NBPF1 gene, will be undertaken in order to analyze the function of this intricate gene in both normal development and tumor pathology. References : Vandepoele, K., Van Roy, N., Staes, K., Speleman, F., and van Roy, F. 2005. A novel gene family NBPF: intricate structure generated by gene duplications during primate evolution. Mol Biol Evol . 22:2265-74. Laureys, G., Speleman, F., Versteeg, R., van der Drift, P., Chan, A., Leroy, J., Francke, U., Opdenakker, G. and Van Roy, N. (1995) Constitutional translocation t(1;17)(p36.31-p36.13; q11.2q12.1) in a neuroblastoma patient. establishment of somatic cell hybrids and identification of PND/a12m2 on chromosome 1 and NF1/SCYA7 on chromosome 17 as breakpoint flanking single copy markers. Oncogene , 10 , 1087-1093. I agree to have the abstract released on the BACR website before the conference in January 2007 .